Which method makes the seed coat permeable and allows growth of embryo ?

Options

A. vernalisation
B. stratification
C. denudation
D. scarification

Explanation

**Step-by-Step Solution:**

1. **Understanding Seed Coats**: Seed coats are protective layers surrounding seeds. They can be tough and impermeable, which prevents water and oxygen from entering the seed and thus inhibits germination.

2. **Identifying the Process**: To allow the growth of the embryo within the seed, the seed coat must become permeable. The process that achieves this is known as **scarification**.

3. **Definition of Scarification**: Scarification involves causing a certain amount of damage to the seed coat. This can be done through various methods, including:
- **Physical Methods**: Using tools like a scalpel or hammer to physically break or scratch the seed coat.
- **Chemical Methods**: Treating the seed coats with mild acids to weaken them.

4. **Result of Scarification**: Once the seed coat is scarified, it becomes permeable to water and oxygen. This permeability is crucial for the germination process, allowing the embryo to grow.

5. **Comparison with Other Methods**:
- **Vernalization**: A process involving exposure to low temperatures to promote flowering in certain plants, but it does not affect seed coat permeability.
- **Stratification**: Involves moistening seeds and exposing them to low temperatures to induce germination, but it does not make the seed coat permeable.
- **Denudation**: This term is not relevant to making seed coats permeable.

6. **Conclusion**: The correct answer to the question is that **scarification** is the method that makes the seed coat permeable and allows the growth of the embryo.

**Final Answer**: Scarification (Option 4).

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